2D layers of interconnected reduced graphene oxide with vanadium disulfide photocatalysts for Rhodamine B degradation

Abstract

Significant concern has been raised on water remediation processes because of the Fourth Industrial Revolution. Toxic organic chemical compounds generated as industrial waste directly spoil the aquatic environment. Thus, the development of photocatalysis is advancing because of the need to clean refractory organic effluents without causing secondary contamination. This work presents a distinctive method for fabricating a novel, efficient, and low-cost rGO-VS2 hybrid composite for photocatalytic dye degradation. The lattice spacing in rGO-VS2 confirmed the compact structure between rGO (0.33 nm) and VS2 (0.57 nm). The photocatalytic performance of the rGO-VS2 composite was determined by the degradation of Rhodamine B (RhB) dye by various optimization processes involving multiple arrays between rGO and VS2 and the effect of the catalyst dosage. The rVS2-3 photocatalyst shows better performance in degradation of RhB because after the addition of VS2 with rGO, the band gap of VS2 decreases from 1.92 to 0.89 eV. Among various materials, 50 mg of rVS2-3 photocatalyst at pH 6 provides excellent degradation efficiency (84.7%) and the highest reproducibility. The trapping test revealed that the direct oxidation of holes (h+) and hydroxyl radical (OH•) plays significant role while superoxide radical (O2•−) acts as secondary active species. The rVS2-3 provides more significant benefits during the dye degradation process, mainly by boosting hydroxyl radical (OH•) generation, effectively influencing the breakdown of the RhB dye molecules into minor toxic forms and minerals.